Pooled transport and control functions in a 3gpp lte network

ABSTRACT

Presented are methods and apparatus for decoupling transport and control (T&amp;C) functions from a plurality of eNBs and collecting the T&amp;C functions in a centralized entity for managing the T&amp;C functions for a larger pool of eNBs. An enhanced interface and protocol is defined for allowing the new T&amp;C pool entity to communicate with the eNBs over a shared IP based network. The redistributed functionality provides for optimizing both data compression capabilities and security by compressing data earlier in its transmission path and by encrypting data before it is sent to an eNB.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/495,184, filed Jun. 13, 2012, which claims priority to Ser. No.11/642,202, filed Dec. 20, 2006, now U.S. Pat. No. 8,213,300, issuedJul. 3, 2012, the entirety of which both are incorporated herein byreference.

TECHNICAL FIELD

The present invention relates generally to telecommunications systems,and in particular, to methods, systems, devices and software fordecoupling Packet Data Convergence Protocol (PDCP) and Radio LinkControl (RLC) protocol functions from an eNode-B entity.

BACKGROUND

Existing Third Generation Partnership Program (3GPP) universalterrestrial radio access networks (UTRAN) 100, such as a wideband codedivision multiple access (WCDMA) network or a universal mobiletelecommunications system (UMTS) network, depicted in prior art FIG. 1,split the UTRAN 102 into two entities. The first entity is a RadioNetwork Controller (RNC) 104 and the second entity is a node-B 106. TheRNC 104 controls the node-B 106 devices to which it is connected byproviding radio resource management and a portion of the mobilitymanagement functions. The RNC 104 also provides dataencryption/decryption services to protect the user data from beingcompromised while in transit to and from the user equipment (UE) 108.The node-B 106 provides the transmitter and the receiver forcommunicating with the UEs 108 within the defined area of the cell. Inorder to facilitate the handover of a UE 108 from one node-B 106 toanother node-B 106 under the control of a different RNC 104, as the UE108 changes geographical location, the RNCs 104 must communicate withboth the core network 110 and the neighboring RNCs 106.

In contrast to the 3GPP UTRAN 100 of FIG. 1, the Long Term Evolution(LTE) based evolved universal terrestrial radio access networks (EUTRAN)100 architecture, depicted in prior art FIG. 2, has removed the RNC 104from the LTE network. The functionality of the RNC 104 has beendistributed to both core network elements, such as the MobilityManagement Entity (MME) 202, and the evolved node-B (eNB) 204. In acomplicating factor, the introduction of a portion of the RNC 106functionality into the eNB 204 has resulted in the requirement for newinter-eNB interfaces 206 and complex hand-off signaling protocols forexchanging information between eNBs 204 as the UE 108 moves around acell and transitions from one eNB 204 to another.

Further, the traditional LTE radio access network (RAN) is comprised ofdistributed eNBs 204 connected to MMEs 202/serving gateways (S-GW)entities via the S1 interface 208 with the eNBs 204 connected to eachother with the X2 interface 206. The LTE eNB 204 hosts functions tosupport Transport and Control (T&C) capabilities such as Radio ResourceManagement (RRM) (i.e., radio bearer control, radio admission control,connection mobility control and dynamic allocation of resources to UEs108 in both uplink and downlink), Internet Protocol (IP) headercompression and encryption of user data stream, selection of MME 202 atUE 108 attachment when no routing to an MME 202 can be determined fromthe information provided by the UE 108, routing of user plane datatoward the S-GW 202, scheduling and transmission of paging messagesoriginating from the MME 202, scheduling and transmission of broadcastinformation originated from the MME 202 or Operations and Maintenance(O&M) and measurement and measurement reporting configuration formobility and scheduling.

As depicted in prior art FIG. 3 of existing 3GPP eNB 302 functions 300,the eNB 302 embodies the T&C functions required by an LTE network suchthat a common shared UTRAN 102 RNC 104 is not required. Specifically,the eNB 302 includes Radio Resource Control (RRC) 304 functions formanaging mobility and radio resources for the UEs 108 in the eNBs 302cell coverage area and Packet Data Coverage Protocol (PDCP) 306functions to provide L3 services to the lower layers for user andcontrol plane messages. Examples of the L3 services are in-sequencedelivery of data including duplicate detection and elimination, userplane IP header compression and ciphering of user and control plane dataand integrity protection of user and control plane data. Each eNB 302traditionally supports a small number of cells that cover a tightlycoupled geographical area. The cell count per eNB 302 is usuallylimited, e.g., three cells per eNB 302 and the RRC 304 and PDCP 306functions embedded in the eNB 302 are limited to supporting the cellscontrolled by the eNB 302 and the UE 108 associated with those cells.

Problems associated with the previously described architectures aremagnified by the projected growth in the use of these services. Wirelessbroadband traffic is projected to more than double every year for theforeseeable future. Keeping pace with this growth will require aproportional increase in the number of cells in any given geographicalarea. With the introduction of LTE advanced features to supportheterogeneous networks and the requirement for a larger number of cells,the number of cells in a given geographical area is expected to increaseover one hundred times with the number of inter-cell mobility eventsincreasing proportionally.

Another emerging problem associated with an eNB 302 providing mobilitymanagement functions is the evolutionary trend of network deploymentswhich include Multiple Radio Access Technology (Multi-RAT), i.e.,mobility between different radio access technologies such as WCDMA, WiFiand CDMA. The issue arises because the LTE eNB 302 architecture includesmobility management functions. As a result, part of the mobilitycoordination is distributed at the eNB 302 level requiring the eNB 302to be aware of each of the hardware technologies.

Another issue related to problems with the existing architectureassociated with increasing cell density is the number of user context(e.g., security keys, Robust Header Compression (ROHC), RRC 304 andsession state) transfers between eNBs 302 increase as the number ofmobility events increases. The successful and time sensitive of thisdata is critical for maintaining user sessions while the UE 108 is fromone eNB 302 coverage area to another. Failure to meet the transferrequirements results in dropped calls or sessions. However, meeting thisrequirement is complex and error prone and engineering a RAN to providethe necessary high levels of mobility performance requires a relativelystatic network and significant operational overhead. LTE networks,however, are now in a growth portion of their lifecycle so consequently,maintaining mobility performance in networks that are inherentlynon-static will be problematic and expensive for network operators.Further, MME/S-GW nodes 202 are currently architected to handle arelatively limited number of S1 interfaces. Consequently, these nodeswill struggle to perform efficiently with one hundred times the numberof eNBs 302 deployed.

As depicted in prior art FIG. 4, the interface 410 between the PDCP 406and the RLC 408 is defined as an internal software interface associatedwith an eNB 402. Accordingly, there is no protocol or transportspecified for this interface, i.e., there is no way to distribute theRRC 404 and the PDCP 406 functions outside of the eNB 402. It should benoted in the depicted prior art eNB 402 that the interfaces between thefunctions are not defined by the 3GPP specifications and no mechanismexists allowing the functions to be located in physically separatenetwork elements.

Market pressure is building for a solution that performs efficientlyunder the previously described conditions allowing better networkperformance with lower operating costs and a greater reliabilitycompared to previously described solutions.

ABBREVIATIONS/ACRONYMS

3GPP Third Generation Partnership Program

CDMA Code Division Multiple Access

DRB Data Radio Bearer

EUTRAN Evolved Universal Terrestrial Radio Access Network

GPRS General Packet Radio Service

GTP GPRS Tunnelling Protocol

IANA Internet Assigned Numbers Authority

IP Internet Protocol

LTE Long Term Evolution

MAC Medium Access Layer

MME Mobility Management Entity

Multi-RAT Multiple Radio Access Technology

O&M Operation and Maintenance

PDCP Packet Data Convergence Protocol

PDU Protocol Data Unit

PHY Physical Layer

RAN Radio Access Network

RBS Radio Base Station

RLC Radio Link Control

RNC Radio Network Controller

ROHC Robust Header Compression

RRC Radio Resource Control

RRM Radio Resource Management

SCTP Stream Control Transmission Protocol

S-GW Serving Gateway

SRB Signal Radio Bearer

T&C Transport and Control Functions

TEID Tunnel Endpoint Identifier

UDP User Datagram Protocol

UE User Equipment

UMTS Universal Mobile Telecommunications System

UTRAN Universal Terrestrial Radio Access Network

WCDMA Wideband Code Division Multiple Access

WiFi Trademark for Wireless IEEE 802.11 Standards

SUMMARY

According to one exemplary embodiment, a server for managing transportfunctions for a plurality of eNodeBs (eNBs) over a shared networkcomprises: a processor configured to execute computer instructions and amemory configured to store said computer instructions wherein saidcomputer instructions further comprise: a Packet Data ConvergenceProtocol (PDCP) component configured to manage the transport functionsfor the plurality of eNBs in a manner which is decoupled from saidplurality of eNBs; and a signaling protocol component configured totransmit transport packets between said server and said plurality ofeNBs over said shared network.

According to another exemplary embodiment, a method, stored in a memoryand executing on a processor, for centralizing transport and control(T&C) functions for management of a plurality of enhanced eNodeBs (eNBs)and their associated cells comprising: disposing said T&C functionsassociated with each of said plurality of eNBs at one or more T&C poolentities; coordinating mobility events associated with said plurality ofeNBs between said one or more T&C pool entities using an interface; andtransmitting control signaling and data packets between said pluralityof eNBs and said one or more T&C pool entities using a protocol across ashared network associated with said control signaling and data packets.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate exemplary embodiments, wherein:

FIG. 1 depicts a prior art UMTS network architecture;

FIG. 2 depicts a prior art E-UTRAN;

FIG. 3 depicts a prior art 3GPP eNB and its associated functions;

FIG. 4 depicts a prior art 3GPP LTE software layering architecture;

FIG. 5 depicts an exemplary M-eNB providing the transport and controlfunctions between a MME/S-GW and a large group of cells;

FIG. 6 depicts an exemplary embodiment of a 3GPP E-UTRAN softwarelayering separation with a dedicated T&C pool entity;

FIG. 7 depicts an exemplary embodiment of a MME server and a S-GW serverintegrated with PDCP and RRC functions;

FIG. 8 depicts an exemplary embodiment of an inter-nodal PDCP-RLCinterface between a T&C pool entity and an eNB;

FIG. 9 depicts an exemplary embodiment of T&C pool interfaces andprotocols for PDCP-PDU messaging for a control plane and a user plane;

FIG. 10 depicts an exemplary embodiment of separate Transport andControl entities with a PDCP control interface;

FIG. 11 depicts an exemplary embodiment of a GTPv1-P protocol entity forexchanging PDCP-PDUs;

FIG. 12 depicts an exemplary embodiment of a S1AP-P protocol entity forexchanging PDCP-PDUs;

FIG. 13A depicts an exemplary embodiment of standalone separateTransport and Control entities using a dedicated interface for PDCPcontrol data exchange;

FIG. 13B depicts an exemplary embodiment of Control functions integratedwith MME and standalone Transport entity;

FIG. 13C depicts an exemplary embodiment of Transport functionsintegrated with S-GW and standalone Control entity;

FIG. 13D depicts an exemplary embodiment of Control functions integratedwith MME and Transport functions integrated with S-GW;

FIG. 14 depicts an exemplary method embodiment for centralizingtransport and control functions; and

FIG. 15 depicts an exemplary computing environment for implementingmethods for centralizing transport and control functions.

DETAILED DESCRIPTION

The following detailed description of the exemplary embodiments refersto the accompanying drawings. The same reference numbers in differentdrawings identify the same or similar elements. Also, the followingdetailed description does not limit the invention. Instead, the scope ofthe invention is defined by the appended claims.

Reference throughout the specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with an embodiment is included inat least one embodiment of the present invention. Thus, the appearanceof the phrases “in one embodiment” or “in an embodiment” in variousplaces throughout the specification are not necessarily all referring tothe same embodiment. Further, the particular features, structures orcharacteristics may be combined in any suitable manner in one or moreembodiments.

The exemplary embodiments described herein have a common set ofcharacteristics that can be associated with the exemplary embodiments.Looking now to FIG. 5 and one exemplary embodiment, the PDCP and the RRCfunctions can be decoupled from the eNB entity. In one aspect of thenetwork 500 exemplary embodiment, the computer processing associatedwith the RRC and the PDCP functions is depopulated from the eNB. Itshould be noted in the exemplary embodiment that the depopulated PDCPand RRC functions (L3) from a plurality of eNBs are also known as theT&C pool. Continuing with the exemplary embodiment, the eNBs becomesimpler to manage because they are focused on only the L1 and L2functions. A new entity, a managed eNB (M-eNB) 502, handles the L3 T&Cpool functions. Next in the exemplary embodiment, the L3 T&C poolfunctions can be implemented using general purpose hardware platforms orembedded into existing network elements. Continuing with the exemplaryembodiment, the L3 T&C pool functions are centralized so they provide L3services to a much larger number of eNBs and correspondingly to a muchlarger number of cells 506.

Continuing with the exemplary embodiment, the M-eNB 502 can correlatethe physical, media access and radio link measurements from a largenumber of eNBs (cells), carriers and RATs allowing the M-eNB 502 to makefirst stage radio resource allocations (e.g. frequency selectivescheduling) across a large number of eNBs (cells). It should be noted inthe exemplary embodiment that the resource allocations are relativelylong-lived, on the order of hundreds of milliseconds to seconds. Itshould further be noted in the exemplary embodiment that the transportfunction can be physically separated from the control function,exploiting the fact that transport traffic data and control traffic datavolumes and their associated processor and memory requirements are notsymmetric.

Continuing with the exemplary embodiment, the T&C pool function managesthe correct transmission end user state and end user traffic duringmobility events, therefore eliminating the requirement of eNB to eNBtransfer of state and traffic data. Next in the exemplary embodiment, amodified interface X2′ 504 is deployed between M-eNBs 502 with thenumber of inter-T&C connections being relatively few. Continuing withthe exemplary embodiment, protocols are defined for transmitting controlsignaling and data packets between the eNBs and the T&C pool functionsthrough a shared IP based network. It should be noted in the exemplaryembodiment that existing 3GPP specifications do not provide a signalingprotocol for transmitting T&C packets through a shared network.

Next in the exemplary embodiment, it should be noted that the LTE T&Cfunctions are dedicated to IP packet processing at layer 3 (networklayer) and above for the data plane. For example, data plane securityshould be performed at a network location that is secure and protectedfrom unauthorized access. Continuing with the exemplary embodiment, LTEdata plane functions also include but are not limited to generation andmanagement of encryption and integrity keying material for end usersessions and accordingly, by performing these functions centrally, thedata plane packets are secure during transmission to the eNBs. Thisfeature of the exemplary embodiment provides a greater level of securitythan the existing LTE network, which distributes this functionalitybetween the MME 510 and the eNB with integrity keying material sent fromthe operator's core network to the eNBs, leaving user's data packetswithout 3GPP security applied until they reach the eNB.

According to one exemplary embodiment, IP packet compression using RoHCoffers better performance when compression (signal overhead savings) isaccomplished as close to the operator's network as possible and wheremobility events do not require the complex RoHC state transfer from oneeNB to another. It should be noted in the exemplary embodiment that RoHCstate context is transparent to eNB mobility events.

According to an exemplary embodiment, the T&C architecture comprises aT&C entity such as an M-eNB 502 encompassing PDCP and RRC functions forone or more eNBs. It should be noted in this exemplary embodiment thatthe northbound S1 interfaces 508 from the M-eNB 502 to the MME/S-GW 510remain unchanged.

Looking now to FIG. 6, an exemplary embodiment of the 3GPP E-UTRANsoftware layering separation 600 for a dedicated T&C pool entity, suchas an M-eNB 602 is depicted. It should be noted in the exemplaryembodiment that the software layering separation 600 is divided betweenan evolved control plane 604 and an evolved data plane 606 from the MME608 to the UE 612 in the evolved control plane 604 and from the S-GW 610to the UE 614 in the evolved data plane 606. Next in the exemplaryembodiment, the M-eNB 602 comprises a C pool 616 in the evolved controlplane 604 and a T pool 618 in the evolved data plane 606. Next in theexemplary embodiment, the C pool 616 comprises an RRC component 620 anda PDCP component 622. Continuing with the exemplary embodiment, the Tpool 618 comprises a GTP 624 and a PDCP 626. It should be noted in theexemplary embodiment that the RoHC and the encryption/integrity flowsfrom the M-eNB 602 to the UE 612, 614.

Continuing with the exemplary embodiment, a single eNB can be dedicatedas the T&C provider for a group of eNBs. In this exemplary embodimentarchitecture, all but one of the eNBs in the group can use the resourcesof the T&C eNB. This exemplary embodiment is especially useful when anetwork is comprised of existing eNBs and is being augmented withheterogeneous style small cells. In this exemplary embodiment, the T&CeNB acts as a controller and maintains the T&C context for a largenumber of smaller and simpler eNB elements, providing for thedistribution of the lower layer radio functions while acting as a singlepoint for upper layer control and resource management.

Looking now to FIG. 7, an exemplary embodiment of extending the existingMME 702, S-GW 704 and MME/S-GW 706 nodes responsibilities by integratingthe T&C functions (PDCP/RRC) for one or more cells is depicted. Itshould be noted in the exemplary embodiment that the S1 interfaceassociated with these nodes becomes an internal logical interface withinthe MME 702, S-GW 704 and MME/S-GW 706 nodes.

Looking now to FIG. 8 for another aspect of the exemplary embodiment, asignaling protocol 800 for transmitting the T&C packets over a shared IPnetwork. The exemplary embodiment comprises new interfaces between aneRBS 802 (i.e., eNB) and the T&C pool functions 804 and specifiesprotocols for PDCP-PDU 806 message exchange over an IP network 808.Further in the exemplary embodiment, an interface and protocol 810 isdefined for exchanging PDCP control data between the user planetransport and the control plane functions for applications when thesefunctions are not co-located. It should be noted in the exemplaryembodiment that the IP network 808 can use UDP 812 or SCTP 814 over theIP network 808.

Looking now to FIG. 9 for another aspect of the exemplary embodiment,new interfaces and protocols 900 are depicted. Continuing with theexemplary embodiment, the 3GPP TS 36.412 “S1 Signaling Transport” and TS36.413 “S1 Application Protocol (S1AP)” for the control plane,incorporated herein by reference and 3GPP TS 36.414 “S1 Data Transport”and TS 29.281 “General Packet Radio System Tunneling Protocol User Plane(GTPv1-U)” for the user plane, incorporated herein by reference, areextended to support transporting PDCP-PDUs through the E-UTRAN network,i.e., exchanging PDCP-PDU messages between network nodes across a sharedcommunications network such as but not limited to an IP network. Itshould be noted in the exemplary embodiment that these extendedinterfaces and protocols are labeled as Sx-PDCP-c 902 for the controlplane and Sx-PDCP-u 904 for the user plane. It should further be notedin the exemplary embodiment that the Sx-PDCP-c 902 interface andprotocol provides communication capabilities between the T&C poolfunctions 906 and the eNB 914 in the control plane and the Sx-PDCP-u 904interface and protocol provides communication capabilities between theT&C pool functions 908 and the eNB 916 in the user plane.

Continuing with the exemplary embodiment, although the S1-MME interfaceand protocol between the T&C pool functions 906 and the MME 910 and theS1-U interface and protocol between the T&C pool functions 908 and theS-GW 912 remains unchanged, the T&C pool functions 906, 908 can beintegrated with existing network elements such as but not limited to aUTRAN RNC or a UTRAN MME and S-GW (e.g. the control functions RRC andPDCP for RRC can be integrated with the RNC and the user plane trafficPDCP functions can be integrated with the S-GW). It should be noted inthe exemplary embodiment that the extended interfaces 902, 904 can existas a single physical interface using either the same or differentprotocols. It should further be noted that the T&C pool 906, 908 is afunctional entity rather than a physical node and can be located in aseparate, stand-alone node or integrated and co-located within existingnodes such as but not limited to the MME 910 and the S-GW 912.

Looking now to FIG. 10, an exemplary embodiment with the control planeand user plane functions instantiated in separate nodes 1000 isdepicted. Continuing with the exemplary embodiment, an interface isdefined to exchange PDCP control data between the control node 1002 andthe transport node 1004. It should be noted in the exemplary embodimentthat this node is labeled the PDCP Ctrl 1006. It should further be notedin the exemplary embodiment that this interface can use, but is notlimited to, the GTPv1-P protocol or the S1AP-P protocol for exchangingPDCP control data between the nodes 1002, 1004. It should also be notedin the exemplary embodiment that when the transport and/or controlentity is integrated into the S-GW or the MME node, the PDCP controldata can be included as new information elements within the existing S11interface, i.e., 3GPP TS 23.401, incorporated herein by reference, andTS 36.300, incorporated herein by reference.

Continuing with the exemplary embodiment, the PDCP-PDUs can beencapsulated and transported using the existing GTPv1-U protocol and/orS1AP protocol with modifications. It should be noted in the exemplaryembodiment that the control and user plane traffic messages sent overthe interfaces can be sent using the modified 3GPP TS 36.414 S1-Uinterface protocol described herein. In an alternative exemplaryembodiment, the control and user plane traffic messages sent over theSx-PDCP-c and Sx-PDCP-u interfaces can be sent using the modified 3GPPTS 36.412 signaling transport and the TS 36.413 S1AP interface protocolas described herein. In another aspect of the exemplary embodiment, thecontrol messages sent over the Sx-PDCP-c interface can be sent over themodified 3GPP TS 36.412 S1AP interface protocol as described hereinwhile the user plane messages sent over the Sx-PDCP-u interface can besent over the modified 3GPP TS 36.414 S1-U interface protocol describedherein. It should be noted in the exemplary embodiment that the messagesequences between the T&C pool and the RBS (eNB) match those of the S1APand the GTPv1-U specifications.

In another aspect of the exemplary embodiment, the T&C pool entity canefficiently discriminate the traffic from existing traditional eNB cellsusing a standard S1-U and S1-C interface from M-eNB cells describedherein, this ability provides for a simpler network deployment byallowing the multiplexing of traffic from all existing eNB cells andM-eNB cells to interface with a T&C pool entity. Further in theexemplary embodiment, as eNB cells are upgraded to use the T&C pool fortheir PDCP and RRC functions, the T&C pool does not require anyreconfiguration for its' interfaces to the subject eNB.

Looking now to FIG. 11, an exemplary embodiment GTPv1-P protocol entity1100 for exchanging PDCP-PDUs is depicted. The exemplary embodimentprotocol entity 1100, based on the GTPv1-U protocol, is used to defineGTPv1-P tunnels for carrying encapsulated PDCP-PDU messages between agiven pair of GTPv1-P entities. Continuing with the exemplaryembodiment, the GTPv1-P protocol entity 1100 provides packettransmission and reception services to PDCP 1106 and RLC 1108 entitiesin the T&C pool 1102 and the M-eNB 1104. Next in the exemplaryembodiment, the GTPv1-P protocol entity receives traffic from a numberof GTPv1-P tunnel endpoints and transmits traffic to a number of GTPv1-Ptunnel endpoints. It should be noted in the exemplary embodiment thatproviding for the coexistence of existing GTPv1-U interfaces and theGTPv1-P interface described herein, the message header comprises anindication of the message contents so the existing GTPv1-U messages canbe distinguished from the GTPv1-P messages.

TABLE 1 Example GTPv1-P Header Bits Octets 8 7 6 5 4 3 2 1 1 Version 0 10 0 0 2 Message Type 3 Length (1st Octet) 4 Length (2nd Octet) 5 TunnelEndpoint Identifier (1st Octet) 6 Tunnel Endpoint Identifier (2nd Octet)7 Tunnel Endpoint Identifier (3rd Octet) 8 Tunnel Endpoint Identifier(4th Octet)

Continuing with the exemplary embodiment and as illustrated in Table 1,GTPv1-P packets can be distinguished from GTPv1-U packets by setting thefourth bit of the first octet to one. In another aspect of the exemplaryembodiment, the message type field shown in the second octet can be usedto indicate the type of PDCP-PDU contained in the GTPv1-P packet, e.g.,SRB PDCP data PDUs, seven or twelve bit sequence number DRB PDCP dataPDUs, RoHC feedback packet PDCP control PDUs or PDCP status report PDCPcontrol PDUs. Continuing with the exemplary embodiment, the TEID presentin the GTPv1-P header unambiguously identifies which PDCP and RLCinstance maintains a given TEID, i.e., the TEID uniquely identifies aradio bearer.

In another exemplary embodiment, each PDCP-PDU is encapsulated within aGTPv1-P header at the sending node. In one aspect of the exemplaryembodiment the fourth bit in the first octet of the GTPv1-P header isset to one to indicate that this GTPv1-P packet contains a PDCP-PDUpayload. It should be noted in the exemplary embodiment that this bitposition is currently reserved and unused and will be inspected by onlythe M-eNB and the T&C pool entities. Continuing with the exemplaryembodiment, the GTPv1-P packet is then further encapsulated in UDP andIP, according to the GTPv1-U specifications, before transmission towardthe packet destination.

Next in the exemplary embodiment, the destination UDP port can be thesame as the GTPv1-U specifications (3GPP TS 29.281, included herein byreference), i.e., UDP port 2152 or a different port can be used, e.g., aport chosen from within the IANA Registered Ports Range of 1024 to49151. It should be noted in the exemplary embodiment, that choosing adifferent destination port than the port used by the GTPv1-U protocol,the receiving node, e.g., the T&C pool entity or the S-GW, candistinguish messages at the UDP network layer allowing the flexibilityto route the message internally within the node for more efficientprocessing. It should further be noted in the exemplary embodiment thatthe IP and UDP headers are removed at the receiving end of thecommunication and if the GTPv1-P packet was received at a port mutuallyagreed upon for exchanging PDCP-PDUs, the receiving entity can assumethat the received packet contains a PDCP-PDU.

Continuing with the exemplary embodiment, the GTPv1-P header can alsoindicate that the payload of the packet contains a PDCP-PDU. Next in theexemplary embodiment, the payload contents are passed to the PDCPfunctional entity responsible for processing PDCP-PDUs and based uponthe Message Type and the TEID fields in the packet header, the PDCP-PDUcan be associated with the unique PDCP or RLC instance for thatPDCP-PDU.

Looking now to FIG. 12, a diagram of PDCP-PDU messaging based onS1AP/S1-MME protocol 1200 is depicted. The exemplary embodimentcomprises a MME node 1202, a T&C Pool node 1204, an M-eNB node 1206 anda UE node 1208. It should be noted in the exemplary embodiment that theM-eNB node is also known as an evolved RBS node or an evolved eNB node.Continuing with the exemplary embodiment, in order for the T&C pool andevolved eNB to exchange PDCP-PDUs with the existing S1AP protocol andS1-MME interface, a number of extensions are required to the S1APprotocol and optionally to the S1-MME interface. It should be noted inthe exemplary embodiment that the extended protocol is named S1AP-Pherein.

In another aspect of the exemplary embodiment, the S1AP protocol hassignaling messages comprising fields of Message Type, MME UE S1AP ID andeNB UE S1AP ID that will be configured and interpreted in an extendedfashion when the payload contains PDCP-PDU data in order to exchangePDCP-PDUs using S1AP/S1-MME. Next in the exemplary embodiment, the SCTPport can be the same as the S1AP specifications (3GPP TS 36.412,included herein by reference), i.e., UDP port 36412 or a different portcan be used, e.g., a port chosen from within the IANA Registered PortsRange of 1024 to 49151. It should be noted in the exemplary embodiment,that choosing a different destination port than the port used by theS1AP protocol, the receiving node, e.g., the T&C pool entity or theevolved eNB, can distinguish messages at the UDP network layer allowingthe flexibility to route the message internally within the node for moreefficient processing.

Continuing with the exemplary embodiment, the SCTP payload protocolidentifier can be different and the PDCP-PDU shall not be ASN.1 encoded.It should be noted in the exemplary embodiment that the PDCP-PDU shallbe contained be contained within the modified S1AP packets as unmodifiedbyte aligned data. It should further be noted in the exemplaryembodiment that the modifications to the existing S1AP header fieldsallow for the S1AP and S1AP-P traffic to be terminated and processedseparately by the same entity, e.g., the T&C pool entity.

Looking now to FIG. 13, four exemplary PDCP control interfaces where thetransport and control entities are separated by a shared network aredepicted. It should be noted in the exemplary embodiment that PDCPcontrol data can be exchanged via either one or a combination of theGTPv1-P, S1AP-P and the s11 interface protocols. Continuing with theexemplary embodiment and looking to FIG. 13A, the PDCP control data isexchanged between the T 1304 and C 1306 nodes using either GTPv1-P orS1AP-P messaging 1302. Next, looking to FIG. 13B of the exemplaryembodiment, the PDCP control data is exchanged between the T node 1308and the MME+C node 1310 using GTPv1-P messaging 1314 between the T node1308 and the S-GW node 1312 and the S11 interface messaging 1316 betweenthe S-GW node 1312 and the MME+C node 1310. Continuing with FIG. 13C ofthe exemplary embodiment, the PDCP control data is exchanged between theSGW+T 1318 and the C node 1320 using S1AP-P protocol messaging 1324between the C node 1320 and the MME node 1322 and S11 interfacemessaging 1326 between the MME node 1322 and the S-GW+T node 1318. Next,looking to FIG. 13D of the exemplary embodiment, the PDCP control datais exchanged between the S-GW+T node 1324 and the MME+C 1326 node usingthe S11 protocol messaging 1328 between the S-GW+T node 1324 and theMME+C node 1326. It should be noted in the exemplary embodiment that foreach of the aforementioned configurations the transport and controlfunctions can similarly be integrated with a UTRAN RNC node. Continuingwith the exemplary embodiment, the RNC can integrate the controlfunctions for the LTE network while the transport is optimally routeddirectly between the S-GW containing the transport functions and theeNB. In another aspect of the exemplary embodiment, the transportfunctions can be integrated into an eNB.

Embodiments described herein can provide various advantages andbenefits. For example, T&C functions can scale to support very largenumbers of eNB cells, potentially tens of thousands; smaller, simplerand cheaper eNBs because fewer functions residing at the eNB; end userdata plane security is applied at a centralized entity without thedistribution of sensitive keying material to remote, potentially lesssecure eNB sites, i.e., the data plane packets are secured from the T&Cfunction to the UE; IP layer 3 and layer 4 services, such as but notlimited to RoHC can be applied nearer to the operator's core networkallowing the IP network to the eNB to benefit from these services,allowing more of the network to benefit from the data compression thatRoHC provides, e.g., reducing traffic in the operator's network; the T&Centity can correlate PHY, MAC and RLC measurements from a large numberof eNBs allowing it to make first stage radio resource allocations,e.g., frequency selective scheduling, wherein these resource allocationsare relatively long lived (100 s of milliseconds to seconds) allowingthe radio resources to be utilized in a more efficient manner which willincrease the capacity of the eNB cells managed by the T&C pool; thisarchitecture allows the development of separate hardware platformsdedicated to either forwarding user traffic or controlling user sessionsand cell resources wherein the asymmetry of the user traffic and controltraffic allows the hardware platforms to be cost optimized for aspecific task. It should further be noted that the protocol allows theT&C pool entity to be integrated into the MME and the S-GW nodes or tobe located in separate nodes.

Looking now to FIG. 14, an exemplary method embodiment 1400 forcentralizing transport and control functions for efficient management ofa plurality of eNBs and their associated cells is depicted. First atstep 1402 of the exemplary method embodiment 1400, the transport andcontrol functions contained in the eNB are decoupled from each of theplurality of eNBs and relocated to the T&C pool entities. It should benoted in the exemplary method embodiment 1400 that a T&C pool entity canbe but is not limited to an existing network node or a general purposehardware node.

Next, at step 1404 of the exemplary method embodiment, an interface iscreated and deployed to the T&C pool entities for communication betweenthe T&C pool entities and coordinating mobility events between the T&Cpool entities. It should be noted in the exemplary method embodimentthat the created protocol can be enhancements to an existing protocolthat allow a node to simultaneously process packets from existing eNBsand from the enhanced eNBs described herein.

Next, at step 1406 of the exemplary method embodiment, a protocol iscreated and deployed to the eNBs and to the T&C pool entities fortransmitting control signaling and data packets between said eNBs andsaid one or more T&C pool entities over a shared network. It should benoted in the exemplary method embodiment that the created protocol canbe an enhancement to an existing protocol. It should further be noted inthe exemplary embodiment that the shared network can be an IP network.

Looking now to FIG. 15, an example of a suitable computing systemenvironment 1500 in which the claimed subject matter can be implemented,although as made clear above, the computing system environment 1500 isonly one example of a suitable computing environment for an exemplaryembodiment and is not intended to suggest any limitation as to the scopeof use or functionality of the claimed subject matter. Further, thecomputing environment 1500 is not intended to suggest any dependency orrequirement relating to the claimed subject matter and any one orcombination of components illustrated in the example computingenvironment 1500.

Continuing with FIG. 15, an example of a device for implementing thepreviously described innovation includes a general purpose computingdevice in the form of a computer 1510. Components of computer 1510 caninclude, but are not limited to, a processing unit 1520, a system memory1530, and a system bus 1590 that couples various system componentsincluding the system memory to the processing unit 1520. The system bus1590 can be any of several types of bus structures including a memorybus or memory controller, a peripheral bus, and a local bus using any ofa variety of bus architectures.

Computer 1510 can include a variety of computer readable media. Computerreadable media can be any available media that can be accessed bycomputer 1510. By way of example, and not limitation, computer readablemedia can comprise computer storage media and communication media.Computer storage media includes volatile and nonvolatile as well asremovable and non-removable media implemented in any method ortechnology for storage of information such as computer readableinstructions, data structures, program modules or other data. Computerstorage media includes, but is not limited to, RAM, ROM, EEPROM, flashmemory or other memory technology, CDROM, digital versatile disks (DVD)or other optical disk storage, magnetic cassettes, magnetic tape,magnetic disk storage or other magnetic storage devices, or any othermedium which can be used to store the desired information and which canbe accessed by computer 1510. Communication media can embody computerreadable instructions, data structures, program modules or other data ina modulated data signal such as a carrier wave or other transportmechanism and can include any suitable information delivery media.

The system memory 1530 can include computer storage media in the form ofvolatile and/or nonvolatile memory such as read only memory (ROM) and/orrandom access memory (RAM). A basic input/output system (BIOS),containing the basic routines that help to transfer information betweenelements within computer 1510, such as during start-up, can be stored inmemory 1530. Memory 1530 can also contain data and/or program modulesthat are immediately accessible to and/or presently being operated on byprocessing unit 1520. By way of non-limiting example, memory 1530 canalso include an operating system, application programs, other programmodules, and program data.

The computer 1510 can also include other removable/non-removable andvolatile/nonvolatile computer storage media. For example, computer 1510can include a hard disk drive that reads from or writes tonon-removable, nonvolatile magnetic media, a magnetic disk drive thatreads from or writes to a removable, nonvolatile magnetic disk, and/oran optical disk drive that reads from or writes to a removable,nonvolatile optical disk, such as a CD-ROM or other optical media. Otherremovable/non-removable, volatile/nonvolatile computer storage mediathat can be used in the exemplary operating environment include, but arenot limited to, magnetic tape cassettes, flash memory cards, digitalversatile disks, digital video tape, solid state RAM, solid state ROMand the like. A hard disk drive can be connected to the system bus 1590through a non-removable memory interface such as an interface, and amagnetic disk drive or optical disk drive can be connected to the systembus 1590 by a removable memory interface, such as an interface.

A user can enter commands and information into the computer 1510 throughinput devices such as a keyboard or a pointing device such as a mouse,trackball, touch pad, and/or other pointing device. Other input devicescan include a microphone, joystick, game pad, satellite dish, scanner,or similar devices. These and/or other input devices can be connected tothe processing unit 1520 through user input 1540 and associatedinterface(s) that are coupled to the system bus 1590, but can beconnected by other interface and bus structures, such as a parallelport, game port or a universal serial bus (USB).

A graphics subsystem can also be connected to the system bus 1590. Inaddition, a monitor or other type of display device can be connected tothe system bus 1590 through an interface, such as output interface 1550,which can in turn communicate with video memory. In addition to amonitor, computers can also include other peripheral output devices,such as speakers and/or printing devices, which can also be connectedthrough output interface 1550.

The processing unit 1520 can comprise a plurality of processing coresproviding greater computational power and parallel computingcapabilities. Further, the computing environment 1500 can contain aplurality of processing units providing greater computational power andparallel computing capabilities. It should be noted that the computingenvironment 1500 can also be a combination of multi-processor andmulti-core processor capabilities.

The computer 1510 can operate in a networked or distributed environmentusing logical connections to one or more other remote computers, such asremote server 1570, which can in turn have media capabilities differentfrom device 1510. The remote server 1570 can be a personal computer, aserver, a router, a network PC, a peer device or other common networknode, and/or any other remote media consumption or transmission device,and can include any or all of the elements described above relative tothe computer 1510. The logical connections depicted in FIG. 15 include anetwork 1580, such as a local area network (LAN) or a wide area network(WAN), but can also include other networks/buses.

When used in a LAN networking environment, the computer 1510 isconnected to the LAN 1580 through a network interface 1560 or adapter.When used in a WAN networking environment, the computer 1510 can includea communications component, such as a modem, or other means forestablishing communications over a WAN, such as the Internet. Acommunications component, such as a modem, which can be internal orexternal, can be connected to the system bus 1590 through the user inputinterface at input 1540 and/or other appropriate mechanism.

In a networked environment, program modules depicted relative to thecomputer 1510, or portions thereof, can be stored in a remote memorystorage device. It should be noted that the network connections shownand described are exemplary and other means of establishing acommunications link between the computers can be used.

Additionally, it should be noted that as used in this application, termssuch as “component,” “display,” “interface,” and other similar terms areintended to refer to a computing device, either hardware, a combinationof hardware and software, software, or software in execution as appliedto a computing device implementing a virtual keyboard. For example, acomponent may be, but is not limited to being, a process running on aprocessor, a processor, an object, an executable, a thread of execution,a program and a computing device. As an example, both an applicationrunning on a computing device and the computing device can becomponents. One or more components can reside within a process and/orthread of execution and a component can be localized on one computingdevice and/or distributed between two or more computing devices, and/orcommunicatively connected modules. Further, it should be noted that asused in this application, terms such as “system user,” “user,” andsimilar terms are intended to refer to the person operating thecomputing device referenced above.

Further, the term to “infer” or “inference” refer generally to theprocess of reasoning about or inferring states of the system,environment, user, and/or intent from a set of observations capturedfrom events and/or data. Captured events and data can include user data,device data, environment data, behavior data, application data, implicitand explicit data, etc. Inference can be employed to identify a specificcontext or action, or can generate a probability distribution overstates, for example. The inference can be probabilistic in that thecomputation of a probability distribution over states of interest basedon a consideration of data and events. Inference can also refer totechniques employed for composing higher-level events from a set ofevents and/or data. Such inference results in the construction of newevents or actions from a set of observed events and/or stored eventdata, whether or not the events are correlated in close temporalproximity, and whether the events and data come from one or severalevent and data sources.

The above-described exemplary embodiments are intended to beillustrative in all respects, rather than restrictive, of the presentinnovation. Thus the present innovation is capable of many variations indetailed implementation that can be derived from the descriptioncontained herein by a person skilled in the art. All such variations andmodifications are considered to be within the scope and spirit of thepresent innovation as defined by the following claims. No element, act,or instruction used in the description of the present application shouldbe construed as critical or essential to the invention unless explicitlydescribed as such. Also, as used herein, the article “a” is intended toinclude one or more items.

1. A method for centralizing transport and control (T&C) functions formanagement of a plurality of evolved nodeBs (eNBs) and their associatedcells, the method comprising: disposing the T&C functions associatedwith each of the plurality of eNBs at at least one T&C pool entity;coordinating mobility events associated with the plurality of eNBsbetween the at least one T&C pool entity using an interface; andtransmitting control signaling and data packets between the plurality ofeNBs and the at least one T&C pool entity using a protocol across ashared network associated with the control signaling and data packets.2. The method of claim 1, wherein the T&C pool entities are embedded inexisting network nodes.
 3. The method of claim 1, wherein the T&C poolentities are embedded in general purpose hardware nodes.
 4. The methodof claim 1, further comprising: correlating, by the at least one T&Cpool entity, PHY, MAC and RLC measurements from the plurality of eNBs;and allocating, by the at least one T&C pool entity, first stage radioresources across the plurality of eNBs based on the measurements.
 5. Themethod of claim 1, further comprising: configuring the T&C pool entitieswith transport functions in a first node and control functions in asecond node.
 6. The method of claim 1, wherein the interface is amodified X2 interface.
 7. The method of claim 1, wherein thetransmitting is performed over a shared IP based network.
 8. The methodof claim 1, further comprising: performing packet compression by the T&Cpool entities before the transmitting.
 9. The method of claim 8, whereinthe packet compression is robust header compression (RoHC).
 10. Anapparatus for centralizing transport and control (T&C) functions formanagement of a plurality of evolved nodeBs (eNBs) and their associatedcells, the apparatus comprising: a processor; and a memory storing aprogram that, when executed by the processor configures the processorto: dispose the T&C functions associated with each of the plurality ofeNBs at at least one T&C pool entity; coordinate mobility eventsassociated with the plurality of eNBs between the at least one T&C poolentity using an interface; and transmit control signaling and datapackets between the plurality of eNBs and the at least one T&C poolentity using a protocol across a shared network associated with thecontrol signaling and data packets.
 11. The apparatus of claim 10,wherein the T&C pool entities are embedded in existing network nodes.12. The apparatus of claim 10, wherein the T&C pool entities areembedded in general purpose hardware nodes.
 13. The apparatus of claim10, wherein the program, when executed by the processor furtherconfigures the processor to: correlate, by the at least one T&C poolentity, PHY, MAC and RLC measurements from the plurality of eNBs; andallocate, by the at least one T&C pool entity, first stage radioresources across the plurality of eNBs based on the measurements. 14.The apparatus of claim 10, wherein the program, when executed by theprocessor further configures the processor to: configure the T&C poolentities with transport functions in a first node and control functionsin a second node.
 15. The apparatus of claim 10, wherein the interfaceis a modified X2 interface.
 16. The apparatus of claim 10, wherein thetransmitting is performed over a shared IP based network.
 17. Theapparatus of claim 10, wherein the program, when executed by theprocessor further configures the processor to: perform packetcompression by the T&C pool entities before the transmitting.
 18. Theapparatus of claim 17, wherein the packet compression is robust headercompression (RoHC).
 19. A non-transitory storage medium storing aprogram, that when executed by a processor causes the processor toperform a method for centralizing transport and control (T&C) functionsfor management of a plurality of evolved nodeBs (eNBs) and theirassociated cells, the method comprising: disposing the T&C functionsassociated with each of the plurality of eNBs at at least one T&C poolentity; coordinating mobility events associated with the plurality ofeNBs between the at least one T&C pool entity using an interface; andtransmitting control signaling and data packets between the plurality ofeNBs and the at least one T&C pool entity using a protocol across ashared network associated with the control signaling and data packets.20. The non-transitory storage medium of claim 19, wherein the methodfurther comprises: configuring the T&C pool entities with transportfunctions in a first node and control functions in a second node.